AAHS Main Site  | Past & Future Meetings  
American Association for Hand Surgery
Meeting Home
Sunglasses
Concert
Poolside
Turtle

Back to 2017 Annual Meeting Program


A Biomechanical Evaluation of a Two Suture Anchor Repair Technique for Thumb Metacarpophalangeal Joint Ulnar Collateral Ligament Injuries
Joseph A Gil, MD; Alison Biercevicz, PhD; Christopher Got, MD; Edward Akelman, MD;
Brown University, Providence, RI

Introduction: A thumb metacarpalphalangeal (MCP) ulnar collateral ligament (UCL) repaired with one suture anchor has been demonstrated to be significantly weaker compared to the intact UCL. Therefore, UCL repairs have been protected and return to full activity has been limited until there is adequate ligament healing which occurs at approximately 10 weeks. More recently, there has been a report of successful, early return to football for patients with a two-anchor UCL repair at 4 weeks after surgery. We hypothesize that this two anchor repair is significantly weaker than the intact UCL ligament.

Methods: Nine paired fresh frozen hands were used for this biomechanical analysis. From each pair, one thumb was randomized to the control group and the contralateral side was assigned to the repair group. Care was taken to dissect all the soft tissues off of the thumb, leaving only the ulnar collateral ligament attached to the first phalanx and the metacarpal. In the control group, the specimen was mounted to the base of a servohydraulic materials test frame (MTS 810, Eden Prairie, MN) using a X-Y translational platform and the UCL was loaded to failure. In the repair group, the UCL was dissected off of the proximal phalanx and subsequently repaired with a two anchor technique. Each repaired specimen was mounted to the servohydraulic materials test frame and the UCL was loaded to failure.

Results: The mean age of the cadavers was 52.6 14.9. The mean yield load (N) was 342 N (95% Confidence Interval (CI), 215-470 N) in the control group and 68 N (95% CI, 45-91 N) in the repair group (P=0.0003). The mean maximum load at failure (N) was 379 N (95% CI, 246-513 N) in the control group and 84 N (95% CI, 62-105 N) in the repair group (P=0.0003). The mean stiffness was 72 N/m (95% CI, 48-96 N) in the control group and 17 N/m (95% CI, 13-21 N) in the repair group (P=0.0002). The mean displacement at failure was 7.8 mm (95% CI, 7-9 N) in the control group and 7.8 mm (95% CI, 7-9 N) in the repair group (P=0.4928).

Conclusions: Our results suggest that while the tested two anchor repair technique does not compromise the structural properties of the thumb UCL tissue, it is not initially possible to reestablish the strength of the insertion of the native insertion of the UCL with this surgical technique.


Back to 2017 Annual Meeting Program